Process of utilizing flue-dust.



.furnace.

UNITED STATES PATENT O FICE. j

EZRA FIWOOD, OF NEW YORK, N. Y. ASSIGNOR TO INTERNATIONAL NICKELCOMPANY, 0 NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

PROCESS OF UTILIZING FLUE-DUST.

Application filed October 20, 1906. Serial No. 339,741.

Process of Utilizing Flue-Dust, of which the following is aspecification.

In the smelting of the ores of cop er and of copper and nickel, muchdifiicu ty has been experienced. by; reason of the losses occasioned bythe flue dust; that'is, the fine particles of the charge of the smeltingfurnace which are carried out with the furnace ases and are deposited inthe outlet fiues. '1 here is ordinari y a loss. of from five to eightper cent. of the ore char e of the furnace due to this cause. Many eorts have been made to utilize'this fluedust by resmelting it in the If.the dust is briqueted for this purpose, that is to say, corn ressedinto small briquets or cakes, the wor of making the briquetssufficiently strong for the purpose is expensive and the result is, atbest, unsatisfactory, for the briquets are generally friable and go topieces in the furnace. If the flue dust is wetted and is charged backdirectly into the furnace, it occasions serious difliculties, because alarge part of'it is carsultant mass to i-naintainthe required coml riedout of the furnace with thengases, thus increasing the percentage ofdust deposited in the fines and diminishlng greatly the workingefficiency of the furnace. The matter, therefore, is a very serious oneto the operators of furnaces, but it is met satisfactorily by myinvention, which consists in taking the flue dust and mixing'the fluedust with a portion of green ore sufficien'tto augment the sulfurcontents of the flue dust, then placing the mixture in a suitablereceptacle or furnace, heatin it, preferably by means of a charge ofcolic or woodignited at its base, and then blowing air through it. Thiscauses the ignition of the mixture and combustion of the sulfur contentsthereof, which raises the mixture graduall I to a heat sufficient tocause a sinterin of t ev mass into a coherent body which can e removedfrom the furnace and broken up into pieces. These pieces aresufficiently strong to hold together in the blast furnace and can besmelted with great economy without materially increasing the percentageof flue dust.

In the conduct ofcthc process, thcmixture of ore and llue dust should bemade so as to give a proper proportion of sulfur in the re-Specification of Letters Patent.

Patented April 14, 1908.

bustion, and the blast of air through the mass should be controlled.

become too rapid, it results in a general chilling of the material,which retards the operathe material in spots. The operation of blowingthe air through the material will continue about four to eight hours, itbeing readily controlled by the operator, who continues it long enoughto bring the charge to the temperature at which it sinters.

,To indicate the proportions which I deem best suited for the practiceof my invention, I will state the following, although it will beunderstood by those skilled in the art that these proportions aregivenas illustrative, and that they may be ,varied within considerable limitsin accordance with the articular kind of ore and flue dust which is tobe treated. I take ore which may contain approximately the followingcomposition:

Copper 1.69 per. cent, Nickel. 5.13 per cent, Iron 45.70 per cent.,Silicon 9.65 per cent, Sulfur -27.?9 per cent.

I mix this green ore with flue dust, referably in about equalproportions. T 1e flue dust may contain the. same elements as the ore,the proportions differing by reason of a lesser content of sulfur. inthe flue dust, which is generally about eight er cent.

equal proportions, are placed in the furnace and treated as abovestated.

Without limiting my invention to the precise proportions and details ofoperation above described,-.since thesemay be varied by those skilled inthe art within the scope of the inventionas defined in the claims,

What I claim is:

1. The method herein described of utilizing flue dust of sulfur-bearingores, which consists in mixing such flue dust with ore richer in sulfurthan the flue dust, igniting causing thereby a sintering of the mixture.

2. The method herein described of utilizing flue dust of sulfur-bearingores, which consists in mixingsuch flue dust with green orc richer insulfur than the flue dust, igniti causing thereby a sintering of themixture.

3. The method here n described of utiliztion, and is apt to causeexcessive heating of the mass, blowing air therethroughpand If it ispermitted to Such ore-and fine dust being mixer in about ing the mass,blowing air therethrough, and 7 ing fiue d'ust of sulfur-bearing ores,which flue dust, igniting the mess, blowing air consists in mixing suchflue-dust with ore theretln'ough, and causing thereby a sinterricher insulfur than flue-dust, Without adin of the mixture.

mixture of carbon or flux, igniting the mass, an testimony whereef, Ihave hereunto set 5 blowing air therethrough, and causing a sinmy hand.

terin of the mixture.

4. "he method herein described of utiliz- EZRA WOOD i g fliie dust ofsulfur-bearing c 0p per and Witnesses:

nickel ores, which consists in mixing such l ALBERT W. JOHNSTON, 1 0flue dHS't WIth ore richer in sulfur than the H. E. F LEWELLIN.

